Here's something I've thought about quite a bit, and I've never had a chance to pose it to any theoretical physicists I come across.
What would happen if you had a disc, say, 10 million miles across, and you spun it. The further out you go, the faster the disc travels, so what happens at the point where the spin speed would exceed the speed of light?
Would the atoms merely separate? I assume the consistency of the disc would have to be broken in some way.
Any thoughts, oh internet?